An EPG and acoustic study of fricative production and spectra

Abstract

In order to test the correspondence between variability in fricative production and variability in the fricative spectrum, the spectral center of gravity (COG) is compared with the EPG center of gravity measured along the horizontal dimension. The CV coarticulatory effects in particular are examined. Data are taken from CV tokens produced by four female speakers of Australian English. Tokens consisted of the coronal fricatives /T s S D z Z/ in seven monophthong vowel contexts. Rounded vowels are excluded so as to minimize spectral changes due to lip-rounding. The consistency between the articulatory and the acoustic data is particularly striking for the palato-alveolar fricatives, although results are also highly consistent for the other two fricative places of articulation examined. However, it is not always clear that the variability in fricative production is conditioned by the vowel context. Overall, the sibilant fricatives seem particularly resistant to coarticulation and to variability in production, while the nonsibilant dental shows a good deal of variability, including some conditioning by the vowel context. These results have implications for the hyper- and hypo-theory of speech production. It is suggested that sibilant fricatives do not lend themselves to the articulatory imprecision, which characterizes other perceptually salient, and typologically common, speech sounds.